Working out how to get more natural light into a house starts with why it's dark. In Sydney the reasons are usually the same: a narrow terrace with walls shared on both sides, a deep plan where the middle rooms are a long way from any window, living areas on the south while the north sun falls on a bedroom or the side passage, or a neighbour's extension that now blocks the sky. Paint and lighting help. But the fix that lasts is getting daylight to where you spend your time, without turning those rooms into ovens in January.
This guide covers how to get more natural light into a house in Sydney, which options suit which rooms, what they cost in 2026, and the rules that decide where glass can go.
How to get more natural light into a house without the heat
Start with north-facing windows and the right eaves. In Australia the sun is in the northern sky. The Australian Government's Your Home guide says north-facing rooms get sun for the longest part of the day in winter and are easily shaded by the eaves in summer. That's why most northern-hemisphere advice about "dark north-facing rooms" doesn't apply here.
The sun angle explains it. At midday in midwinter, the sun in Sydney sits about 33° above the horizon, according to the NSW Apartment Design Guide, so it reaches deep into a north room. In midsummer it's about 79°, nearly overhead, and a modest eave keeps it off the glass.
Your Home gives a simple rule for Sydney's latitude: make the eave about 45% of the height from the window sill to the underside of the eave. For a typical sill-to-eave height of 1.35 to 2.1 m, that's an overhang of about 900 mm.
East and west glass are harder. Low morning and afternoon sun comes in sideways, under any eave. Your Home suggests keeping east and west glazing to a minimum, or using adjustable external shading such as outdoor blinds. A big unshaded west window is one of the most common reasons a new extension is unbearable on summer afternoons.
Glass also loses heat. Your Home says up to 87% of a home's heat gain and up to 40% of its heating loss can happen through windows. More glass is only better if it's on the right side and shaded.
How much natural light does the building code require?
The building code sets the minimum for every habitable room (living rooms, bedrooms, kitchens, dining rooms and studies). NCC 2022 is in force in NSW until NCC 2025 is adopted on 1 May 2027.
| Rule | What it says |
|---|---|
| Windows | Glass of at least 10% of the room's floor area, facing the sky or an open space |
| Roof lights | Skylights of at least 3% of the floor area, or a mix of windows and roof lights |
| Near a boundary | A window needed for natural light, facing a neighbour's boundary, must be at least 900 mm from it |
| Borrowed light | A room can be lit through an adjoining room, if the glass between them is at least 10% of the room's floor area and the other room has enough windows for both |
| Bathrooms and laundries | Artificial light is enough where there's no natural light |
The roof light figure is lower because a skylight sees the whole sky. The 900 mm rule matters in terraces and semis: a side window right on the boundary may not count toward the room's daylight.
Councils can ask for more. In Leichhardt, every habitable room needs daylight from a window to the outside or onto a courtyard or light well, regardless of any skylights. A skylight on its own won't satisfy that.
Skylight, roof window or solar tube?
Each has its place. Your Home's figures are the key: a skylight or roof window can admit more than three times as much light as a vertical window the same size, but roof glass receives almost twice as much heat as an unshaded west-facing window.
| Option | Best for | What to watch | Indicative cost |
|---|---|---|---|
| Fixed skylight with a shaft | Hallways, stairs, middle rooms, kitchens | Heat and glare. Needs shading, double glazing and an insulated shaft | Supply from about $560 for a manually opened Velux unit, on a Sydney installer's 2026 price list; installed jobs often about $1,500 to $4,000 nationally, according to a 2026 cost guide |
| Opening roof window | Raked ceilings, attics, two-storey stairwells | Same heat issues. Opening it lets hot air out in summer | Supply about $840 to $3,200 depending on type and motor (same 2026 list) |
| Solar tube (tubular skylight) | Windowless bathrooms, walk-in robes, laundries, halls | Little heat, but no view or sky, and less light on cloudy days | About $350 to $2,000 installed, in a 2024 guide from a tube manufacturer |
| Clerestory (high) windows | Deep rooms, south rooms behind a raised roof | Shade north ones with an eave; double glaze | Depends on the roof work |
Size them modestly. Your Home suggests a skylight area of about 3 to 5% of the room's floor area, or 1 to 2% for a good tubular skylight. For a 20 m² living room, that's 0.6 to 1 m² of skylight, or 0.2 to 0.4 m² of tube. Quite small skylights deliver a lot of light.
A few rules of thumb:
- Not over a bed, a desk or the TV. Direct sun means glare, early mornings and heat where you least want them.
- Shade the ones on north and west roof slopes. An external blind or louvre is most effective. A south-facing roof slope gives softer, cooler light.
- Use diffused glass where you want even light. It spreads the light and cuts glare.
- In bathrooms, avoid uninsulated metal frames, which can cause condensation in cooler weather.
- Keep leaves off. Your Home suggests cleaning every two years, or every six months near the sea or under trees.
How do you light the middle of a terrace or semi?
From above, or from a courtyard in the middle. In a terrace with shared walls on both sides, light can only come from the front, the back and the roof. Removing internal walls helps spread it, but doesn't add any.
The options that work:
- A light well or small courtyard at the join between the old house and the extension. Your Home suggests reconfiguring layouts to add light wells or internal courtyards with new north-facing walls. As a size benchmark, the NSW low-rise design guide asks for courtyards open to the sky with a minimum width of a third of the surrounding wall height and an area of at least 4 m².
- A skylight over the stair, so the stair becomes a light shaft into the middle of the house.
- A raised section of roof with north-facing clerestory windows.
- A glazed roof over the side passage, where the council allows the passage to be enclosed. Leichhardt's controls allow it only where the neighbour's sun, privacy and airflow aren't harmed.
At Everleigh, a Victorian terrace in Balmain, an L-shaped skylight opens up the floor plan and brings light into the heart of the home. At The Duet in Marrickville, the rear of the duplex faces south, so the home was planned to bring warm northern light into the back courtyard, with skylights and full-height glass around a spiral stair keeping the inside bright.
Note one weakness of light wells. Leichhardt's controls say direct sun to a light well or courtyard on a shared side boundary isn't protected, so a neighbour's future extension could shade it. Keep a window to the outside for the main living room as well.
Can glass doors and internal windows share the light?
Yes, they spread light that's already coming in. Your Home suggests glass panels over doors, glazed sections in internal walls and light-coloured surfaces to reflect more light indoors. A glass door between the living room and a hallway can turn a dark corridor into a bright one.
Internal glass adds light; it can't be the only source for a main room where council rules need a window. Glass in doors, beside doors and close to the floor must be safety glass under the building code. Our guide to making a small house feel bigger covers internal windows and borrowed light in more detail.
How does BASIX treat extra glass and skylights?
BASIX, the NSW energy and water certificate, applies to alterations and additions worth $50,000 or more, and to every new home. It looks at the thermal performance of new work, and glass is usually the biggest factor.
A few details owners don't expect, from the NSW Planning Portal's BASIX method:
- Solar tubes aren't entered at all.
- A skylight smaller than 0.7 m² can be left out.
- For a new single home using the simpler method, skylights are capped at 3 m² in total, and glazing has to stay between 10% and 40% of the heated and cooled floor area. Beyond that, a full energy simulation is needed.
- Low U-value glass helps in winter, low solar-heat-gain glass helps in summer, and adjustable shading scores better than fixed.
Big unshaded west glass and large skylights are what make a design fail BASIX. North glass with proper eaves, and small or tubular skylights, pass more easily.
What will council say about skylights and new windows?
Three sets of rules come up most.
Heritage. In conservation areas, skylights generally go where the street can't see them. In the former Marrickville area, skylights on terraces and row houses are allowed only on the rear plane of the roof. Inner West's proposed new development control plan, exhibited in 2026, would only consider a discreet skylight where it isn't visible from the main street. Our heritage conservation area guide explains how these areas work.
Approval after the fact doesn't work. In Haberfield, an owner installed six skylights without approval and then applied to keep them. Council's 2022 planning report recommended refusal: the skylights were visible from the street, and council said it had no power to approve works already built through a development application. Some skylights can be installed without approval under the state's exempt development rules, but not on a heritage item, and the limits are detailed. Check with council or a certifier before the roof is cut.
Privacy and the neighbours' sun. New side windows that look into a neighbour's living room or yard may need screening, high sills or frosted glass. Leichhardt's controls, for example, ask for screening within 9 m and 45° of a neighbour's living room window. High windows and skylights avoid most of these conflicts. Councils also protect a minimum amount of winter sun to the neighbours' living rooms and yards, usually two to three hours, so a two-storey extension on the north side of a neighbour can be limited.
What this means for you
Before you design, work through these:
- Find true north on the plan, and note which rooms you use most and when
- Check which side the living areas face, and whether they could move north
- Note any big east or west glass, and plan shading for it
- Mark the dark middle rooms and the options for light from above
- Choose the right tool for each room: window, skylight, roof window, tube or light well
- Keep skylights modest: about 3 to 5% of the room's floor area
- Check heritage rules on where skylights may go, and whether approval is needed
- Check privacy rules for new side windows
- Test the glass early against BASIX
Our feasibility study looks at the orientation, the planning controls and the heritage rules for your property, so the light is planned in from the first sketch. See how we approach renovations and extensions.
Questions people ask
Skylight or solar tube: which is better?
It depends on the room. A solar tube is small, cheaper, adds very little heat and suits a windowless bathroom, walk-in robe or hallway, but you won't see the sky through it and it gives less light on cloudy days. A skylight or roof window lights a living space and shows the sky, but needs shading and double glazing to control heat. Many homes use both.
Do skylights need council approval in NSW?
Sometimes. Some skylights can be installed as exempt development under the state's rules, but that doesn't apply on a heritage item, and conservation areas often limit skylights to roof slopes the street can't see. A skylight that's part of a larger renovation goes into that approval. Council can't approve a skylight after it's built through a development application, so check before cutting the roof.
What are the natural light requirements for habitable rooms in Australia?
Under the building code, each habitable room needs windows with glass of at least 10% of its floor area, or skylights of at least 3%, or a mix. Light can be borrowed through an adjoining room if the glazing between them is large enough, and a window close to a side boundary must be at least 900 mm from it to count. Some councils, including Leichhardt, ask for a real window in every habitable room.
How much does a skylight cost in Sydney?
Prices vary with the type and the roof. A Sydney installer's 2026 list puts a manually opened Velux skylight at about $560 to $1,060 for supply, and a 2026 national cost guide puts most installed skylights at about $1,500 to $4,000, with the shaft being the biggest variable. A tube manufacturer's 2024 guide puts solar tubes at about $350 to $2,000 installed. Get a quote that includes the shaft, flashing, shading and making good.
Sources
- Skylights and roof windows, Your Home, Australian Government
- Shading, Your Home, Australian Government
- Glazing, Your Home, Australian Government
- Orientation, Your Home, Australian Government
- NCC 2022 Housing Provisions, Part 10.5 Light, Australian Building Codes Board
- BASIX DIY method: skylights, NSW Planning Portal (updated October 2026)
- BASIX for alterations and additions, NSW Planning Portal
- Marrickville DCP 2011, Part 4.1 Low Density Residential Development, Inner West Council
- Inner West Local Planning Panel, report on unapproved skylights in Haberfield (September 2022)
- Skylight prices 2026, No 1 Roofing & Gutters (Sydney installer)
